Front face of a vehicle air vent grille insert



FIG. 1 is an top, left, front perspective view of a front face of a vehicle air vent grille insert showing our design; and,

FIG. 2 is a front elevational view thereof.

The rear of the design is omitted and not being claimed. 

CLAIM The ornamental design for a front face of a vehicle air vent grille insert, as shown and described. 